Method Apply

source/fuzz/fuzzer_pass_adjust_function_controls.cpp:30–67

                 transformations, ignore_inapplicable_transformations) {}

void FuzzerPassAdjustFunctionControls::Apply() {
  // Consider every function in the module.
  for (auto& function : *GetIRContext()->module()) {
    // Randomly decide whether to adjust this function's controls.
    if (GetFuzzerContext()->ChoosePercentage(
            GetFuzzerContext()->GetChanceOfAdjustingFunctionControl())) {
      // Grab the function control mask for the function in its present form.
      uint32_t existing_function_control_mask =
          function.DefInst().GetSingleWordInOperand(0);

      // For the new mask, we first randomly select one of three basic masks:
      // None, Inline or DontInline.  These are always valid (and are mutually
      // exclusive).
      std::vector<spv::FunctionControlMask> basic_function_control_masks = {
          spv::FunctionControlMask::MaskNone, spv::FunctionControlMask::Inline,
          spv::FunctionControlMask::DontInline};
      uint32_t new_function_control_mask =
          uint32_t(basic_function_control_masks[GetFuzzerContext()->RandomIndex(
              basic_function_control_masks)]);

      // We now consider the Pure and Const mask bits.  If these are already
      // set on the function then it's OK to keep them, but also interesting
      // to consider dropping them, so we decide randomly in each case.
      for (auto mask_bit :
           {spv::FunctionControlMask::Pure, spv::FunctionControlMask::Const}) {
        if ((existing_function_control_mask & uint32_t(mask_bit)) &&
            GetFuzzerContext()->ChooseEven()) {
          new_function_control_mask |= uint32_t(mask_bit);
        }
      }

      // Create and add a transformation.
      TransformationSetFunctionControl transformation(
          function.DefInst().result_id(), new_function_control_mask);
      ApplyTransformation(transformation);
    }
  }
}

}  // namespace fuzz
}  // namespace spvtools